2000
#12,193
National surname rank
Recorded bearers 2,343
First available Census row
Per 100,000 0.87
Rare Last name
Costigan
An Irish surname derived from the Gaelic "Mac Oistigin," meaning "son of Oistigin," a personal name of unknown meaning.
According to the 2020 US Census Bureau surname tables, roughly 2,725 Americans carry the last name Costigan. That puts it at #12,466 in the national surname ranking, appearing at a frequency of 0.79 per 100,000 people (about 1 in 125,781 residents).
This page is the full Name Census profile for the Costigan surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
For British records, Name Census UK has a British surname profile for Costigan with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
2.7K
1 in 125,781
Census rank
#12,466
2020 decennial data
Per 100,000
0.8
Frequency rate
Recorded bearers
2.4K
rare in the US
Popularity narrative
The Census Bureau recorded 2,376 bearers of the surname Costigan in its 2020 decennial surname file. At a rate of 0.79 per 100,000 residents, it holds the 12466th position in the national surname ranking.
Among Census respondents with the surname Costigan, the largest self-reported group is White at 90.6%. The next largest groups are Hispanic (4.8%) and Two or More Races (3.2%).
Origin
Meaning and origin of Costigan
The surname Costigan originates from Ireland, with its roots dating back to the 16th century. It is derived from the Gaelic name "O'Cuistighean," which means "descendant of the prudent or wise one." The name was widely found in County Mayo and parts of Connacht.
Costigan is believed to have evolved from various spellings, such as "O'Cuistighean," "O'Cuisdighean," and "O'Cuistighne." The prefix "O'" signifies the family's descent from the Irish clan system.
One of the earliest recorded instances of the name Costigan can be found in the Annals of the Four Masters, a chronicle of medieval Irish history compiled in the 17th century. It mentions a notable figure named Turlough Costigan, who was a distinguished scholar and poet in the late 16th century.
In the early 18th century, the Costigan family played a significant role in the Irish Rebellion of 1798. John Costigan (1742-1828), a prominent leader from County Mayo, was actively involved in the uprising against British rule.
Another notable bearer of the Costigan name was John Austin Costigan (1835-1902), an Irish-born Canadian politician who served as a Member of Parliament and played a crucial role in the construction of the Canadian Pacific Railway.
The name Costigan has also been associated with various place names in Ireland, such as Costigan's Cross, a hamlet in County Mayo, and Costigan's Bridge, a landmark in County Sligo.
Throughout history, several other individuals with the surname Costigan have left their mark in various fields, including:
1. George Purcell Costigan (1835-1913), an Irish barrister and judge who served as a Justice of the King's Bench Division of the High Court of Justice in Ireland.
2. John Costigan (1835-1900), an Irish-American soldier who fought in the American Civil War and received the Medal of Honor for his bravery.
3. Michael Costigan (1844-1913), an Irish-born American entrepreneur and real estate developer who played a significant role in the development of Los Angeles.
4. William J. Costigan (1888-1957), an American lawyer and politician who served as a United States Senator from Colorado.
5. John Costigan (1910-2002), an Irish politician and member of Dáil Éireann, representing the Labour Party.
Demographics
Ancestry and ethnicity for Costigan
Among Census respondents with the surname Costigan, the largest self-reported group is White at 90.6%. The next largest groups are Hispanic (4.8%) and Two or More Races (3.2%).
The bar chart below shows how Costigan bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Costigan surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.6% · 2,152
- Hispanic or Latino4.8% · 113
- Two or more races3.2% · 75
- Asian and Pacific Islander0.8% · 19
- Black or African American0.6% · 15
- American Indian and Alaska Native0.1% · 2
Timeline
Historical Census data for Costigan
Costigan appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#12,566
National surname rank
Recorded bearers 2,463
+120 bearers (+5.1%)
Per 100,000 0.83
Rank movement Down 373 places
2020
#12,466
National surname rank
Recorded bearers 2,376
-87 bearers (-3.5%)
Per 100,000 0.79
Rank movement Up 100 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #12,193 | 2,343 | 0.87 | First available Census row | First available Census row |
| 2010 | #12,566 | 2,463 | 0.83 | +120 bearers (+5.1%) | Down 373 places |
| 2020 | #12,466 | 2,376 | 0.79 | -87 bearers (-3.5%) | Up 100 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Costigan surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #12,566 | #12,466 | 0.8% |
| Count | 2,463 | 2,376 | -3.5% |
| Per 100K | 0.83 | 0.79 | -4.2% |
Between the 2010 and 2020 Census, the number of Costigan bearers went from 2,463 to 2,376 (-3.5% change). The surname moved up 100 positions in the national ranking, going from #12,566 to #12,466.
FAQ
Costigan surname: questions and answers
How many people in the U.S. have the surname Costigan?
Name Census estimates that about 2,725 living Americans carry the surname Costigan. Using the current population baseline, that works out to roughly 1 in 125,781 residents.
How common is Costigan?
Costigan ranks #12,466 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.79 per 100,000 residents, which is about 1 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 2,376 people with the surname Costigan. That is different from the site's living-bearer estimate (2,725), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.79 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.79 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 1 of them to have the surname Costigan.
Has Costigan become more or less common over time?
Between 2010 and 2020, the surname Costigan went from 2,463 recorded bearers to 2,376. That is a decrease of 87 (-3.5%). In the national ranking it rose from #12,566 to #12,466.
What does the Census say about the background of Costigan?
Among Census respondents with the surname Costigan, the largest self-reported group is White at 90.6%. The next largest groups are Hispanic (4.8%) and Two or More Races (3.2%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Costigan in the 2020 Census, accounting for 90.6% (2,152 people in the source table).
What is the full ancestry breakdown?
Costigan appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.6%), Hispanic (4.8%), Two or More Races (3.2%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Costigan (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Costigan mean?
An Irish surname derived from the Gaelic "Mac Oistigin," meaning "son of Oistigin," a personal name of unknown meaning. The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Costigan (0.79 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How many people share the surname Costigan?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.